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By Kristie Stoick, M.P.H., and John J. Pippin, M.D., F.A.C.C.
ALTERNATIVES TO ANIMAL RESEARCH
Lab-Grown ‘Livers’ Are Promising Animal-Testing Alternative
Scientists at Newcastle University in northeast England reported in late October that they had succeeded in producing “mini-livers” that might have uses ranging from pharmaceutical testing to human transplantation. The researchers took umbilical cord blood cells from newborn babies and multiplied the cells in a NASA “bioreactor,” allowing the cells to divide into a liver-like tissue more quickly.
These small sections of liver tissue can be used by pharmaceutical companies to check for liver toxicity, a side effect of many new drugs. In the future, the tissue might be used to help a person with liver disease survive until a complete new liver becomes available, or to repair a damaged liver completely.
Millard R. Lab-grown human liver a medical breakthrough.
Independent Online, October 21, 2006.
Endangered Sooty Mangabeys Spared Laboratory Testing
After widespread opposition, Yerkes National Primate Research Center at Emory University has dropped its plan to use 230 captive sooty mangabey monkeys, a subspecies of the endangered white-collared mangabey, in laboratory AIDS experiments. The center had petitioned the U.S. Fish and Wildlife Service (FWS) to allow it to perform fatal experiments on the monkeys because it had been contributing up to $30,000 a year to mangabey conservation efforts in West Africa.
The FWS received 400 to 500 comments from individuals and groups opposing the petition, including noted primatologist Jane Goodall and PCRM. In a victory for the animals, Yerkes withdrew the petition in September. However, a Yerkes spokeswoman said that while the center’s support for mangabey conservation would continue, it “will continue to explore options to involve the center’s mangabey colony in research programs.”
Stobbe, Mike. Researchers abandon monkey experiments. Associated Press. October 24, 2006.
Human and Rodent Pancreas Cells Found to Have Key Differences
Using an exacting technique called confocal microscopy, scientists at the Karolinska Institute in Stockholm, Sweden, and the University of Miami have found that human islets of Langerhans are organized and function much differently compared with rodent cells of the same type. Islets of Langerhans—or islets—are the clusters of insulin-producing cells in the pancreas.
Scientists are attempting to perfect transplantation of islet cells for people with type 1 diabetes. In order to better assess the quality of cells for transplantation, scientists need a good understanding of how normal human islets are structured and how they function. The authors conclude that the prevailing wisdom—that mammalian species have similar islet architecture and function—is incorrect, and further studies are needed on human islets.
Cabrera O, Berman DM, Kenyon NS, Ricordi C, Berggren P, Caicedo A. The umique cytoarchitecture of human pancreatic islets has implications for islet cell function. PNAS. 2006;103(7):2334-2339.
Autopsy Study Reveals Factors Associated with SIDS
Physicians at Harvard University have identified risk factors and pathological abnormalities present in babies who died of sudden infant death syndrome (SIDS). In a comparative analysis of the neural tissue of infants who died of SIDS and infants who died of other causes, the researchers identified deficiencies in the serotonergic system that researchers say could predispose babies to SIDS and might also explain why boys are more susceptible to SIDS. When combined with risk factors such as face-down sleeping, these babies have trouble responding to respiratory troubles or other physiological stressors and could suffocate.
Studies such as this one that focus on human biology sidestep the problems of animal experiments.
Paterson D, Trachtenberg F, Thompson E, et al. Multiple serotonergic brainstem abnormalities in sudden infant death syndrome. JAMA. 2006;296(17):2124-2132.
By Dulcie Ward, R.D., and Susan Levin, M.S., R.D.
Calcium Supplements Fail to Improve Children’s Bone Health
A new analysis shows little benefit to using calcium supplements to improve bone health in children. Nineteen randomized controlled trials were reviewed to determine the effectiveness of calcium supplementation for improving bone mineral density in children. Supplementation had no effect on the bone mineral density in the neck or spine and caused only a small increase in the density of the upper limb, equivalent to a 1.7 percentage increase in the supplemented group compared with the control. No lasting effect of supplementation was seen in the one study that reported total body density after supplementation stopped.
Winzenberg T, Shaw K, Fryer J, Jones G. Effects of calcium supplementation on bone density in healthy children: meta-analysis of randomized controlled trials. BMJ. 2006;333:775.
Fruits and Vegetables Improve Male Fertility
A new study shows that eating fruits and vegetables can improve fertility in men. Researchers from the University of Rochester compared the dietary intake of antioxidants of 10 fertile and 48 infertile men and correlated the findings with sperm motility. Infertile men were twice as likely to have a low intake of fruits and vegetables (fewer than five servings per day) compared with fertile men. Also, men with the lowest overall intake of dietary antioxidants had lower sperm motility than men with higher intakes.
Lewis V, Kochman L, Herko R, Brewer K, Andolina E, Song G. Dietary antioxidants and sperm quality in infertile men.
Paper presented at: Annual Scientific Meeting of the American Society for Reproductive Medicine; October 2006; New Orleans.
Fish Consumption Linked to Premature Birth
Consumption of methylmercury found in fish and shellfish may lead to premature births, according to the Pregnancy Outcomes and Community Health (POUCH) study. The POUCH study enrolled 1,024 women in their 15th to 27th week of pregnancy from 52 Michigan-based clinics and compared self-reported fish intake with mercury levels measured in hair samples. Strong evidence showed that mercury levels in maternal hair were higher when fish consumption was increased. In addition, women who delivered preterm (before 35 weeks) were more likely to be at or above the 90th percentile for mercury contamination than those who delivered at term (at or after 37 weeks). Possible explanations include the oxidative stress imposed by methylmercury on a cellular level and methylmercury’s influence on the functionality of platelets (blood cells necessary for clotting).
Xue F, Holzman C, Rahbar MH, Trosko K, Fischer L. Maternal fish consumption, mercury levels and risk of preterm delivery. Environ Health Perspect. September 25, 2006. Available at: http://www.ehponline.org/members/2006/9329/9329.pdf. Accessed November 21, 2006.